João Santos

Caffeine Exposure and the Risk of Parkinson's Disease: A Systematic Review and Meta-Analysis of Observational Studiess

Several studies conducted worldwide report an inverse association between caffeine/coffee consumption and the risk of developing Parkinsons disease (PD). However, heterogeneity and conflicting results between studies preclude a correct estimation of the strength of this association. We conducted a systematic review and meta-analysis of published epidemiological studies to better estimate the effect of caffeine exposure on the incidence of PD. Data sources searched included Medline, LILACS, Scopus, Web of Science and reference lists, up to September 2009. Cohort, case-control and cross-sectional studies were included. Three independent reviewers selected the studies and extracted the data on to standardized forms. Twenty-six studies were included: 7 cohort, 2 nested case-control, 16 case-control, and 1 cross-sectional study. Quantitative data synthesis of the most precise estimates from each study was accomplished through random effects meta-analysis. Heterogeneity was quantified using the I2 statistic. The summary RR for the association between caffeine intake and PD was 0.75 [[95% Confidence Interval (95%CI): 0.68-0.82], with low to moderate heterogeneity (I2= 28.8%). Publication bias for case-control/cross-sectional studies may exist (Eggers test, p=0.053). When considering only the cohort studies, the RR was 0.80 (95%CI: 0.71-90; I2=8.1%). The negative association was weaker when only women were considered (RR=0.86, 95%CI: 0.73-1.02; I2=12.9%). A linear relation was observed between levels of exposure to caffeine and the RR estimates: RR of 0.76 (95%CI: 0.72-0.80; I2= 35.1%) per 300 mg increase in caffeine intake. This study confirm an inverse association between caffeine intake and the risk of PD, which can hardly by explained by bias or uncontrolled confounding.

Caffeine Intake and Dementia: Systematic Review and Meta-Analysis

A recent meta-analysis of 4 studies published up to January 2004 suggests a negative association between coffee consumption and Alzheimers disease, despite important heterogeneity in methods and results. Several epidemiological studies on this issue have been published since then, warranting an update of the insights on this topic. We conducted a systematic review and meta-analysis of published studies quantifying the relation between caffeine intake and cognitive decline or dementia. Data sources searched included Medline, LILACS, Scopus, Web of Science and reference lists, up to September 2009. Cohort and case-control studies were included. Three independent reviewers selected the studies and extracted the data on to standardized forms. Nine cohort and two case-control studies were included. Quantitative data synthesis of the most precise estimates from each study was accomplished through random effects meta-analysis. Heterogeneity was quantified using the I2 statistic. The outcomes of the studies considered for meta-analysis were Alzheimers disease in four studies, dementia or cognitive impairment in two studies, and cognitive decline in three studies. The summary relative risk (RR) for the association between caffeine intake and different measures of cognitive impairment/decline was 0.84 [95% Confidence Interval (95% CI): 0.72-0.99; I2=42.6%]. When considering only the cohort studies, the summary RR was 0.93 (95% CI: 0.83-1.04, I2= 0.0%), and 0.77 (95% CI: 0.63-0.95, I2= 34.7%), if the most influential study was excluded. This systematic review and meta-analysis found a trend towards a protective effect of caffeine, but the large methodological heterogeneity across a still limited number of epidemiological studies precludes robust and definite statements on this topic. and definite statements on this topic.

European Society of Anaesthesiology and European Board of Anaesthesiology guidelines for procedural sedation and analgesia in adults

&NA; Procedural sedation and analgesia (PSA) has become a widespread practice given the increasing demand to relieve anxiety, discomfort and pain during invasive diagnostic and therapeutic procedures. The role of, and credentialing required by, anaesthesiologists and practitioners performing PSA has been debated for years in different guidelines. For this reason, the European Society of Anaesthesiology (ESA) and the European Board of Anaesthesiology have created a taskforce of experts that has been assigned to create an evidence-based guideline and, whenever the evidence was weak, a consensus amongst experts on: the evaluation of adult patients undergoing PSA, the role and competences required for the clinicians to safely perform PSA, the commonly used drugs for PSA, the adverse events that PSA can lead to, the minimum monitoring requirements and post-procedure discharge criteria. A search of the literature from 2003 to 2016 was performed by a professional librarian and the retrieved articles were analysed to allow a critical appraisal according to the Grading of Recommendations Assessment, Development and Evaluation method. The Taskforce selected 2248 articles. Where there was insufficiently clear and concordant evidence on a topic, the Rand Appropriateness Method with three rounds of Delphi voting was used to obtain the highest level of consensus among the taskforce experts. These guidelines contain recommendations on PSA in the adult population. It does not address sedation performed in the ICU or in children and it does not aim to provide a legal statement on how PSA should be performed and by whom. The National Societies of Anaesthesiology and Ministries of Health should use this evidence-based document to help decision-making on how PSA should be performed in their countries. The final draft of the document was available to ESA members via the website for 4 weeks with the facility for them to upload their comments. Comments and suggestions of individual members and national Societies were considered and the guidelines were amended accordingly. The ESA guidelines Committee and ESA board finally approved and ratified it before publication.

Optimization Framework for Supporting 40 Gb/s and 100 Gb/s Services over Heterogeneous Optical Transport Networks

Continuous traffic growth and crunched profit margins are leading network operators to deploying high-capacity backbone infrastructures with minimal capital investment. However, the cost-effective design of optical transport networks (OTNs) remains a complex challenge subjected to multiple constraints, e.g., maximum bit rate per channel, electrical multiplexing capabilities, wavelength count per fiber, optical interface cost, maximum transparent reach, etc. To efficiently solve this multi-constrained dimensioning problem in presence of heterogeneous client demands and optical channel rates of 40 Gb/s and 100 Gb/s, this paper presents a novel hybrid optimization framework. The proposed approach is based on an iterative combination of linear programming and rounding algorithms for the demand routing, with graph coloring heuristics for the wavelength assignment. The performance of this framework is assessed and compared with a similar approach that resorts to an integer linear programming (ILP) model to route the demands. The results obtained show that our proposal is able to reach the same low network expenditures as the ILP while requesting less computation time. We also confirm that the most cost-effective network solutions are attained when optical line rate heterogeneity is jointly applied with diverse multiplexing capabilities at the OTN electrical layer, such as grooming and inverse-multiplexing.

Design and performance evaluation of protected Super-EPON Access networks using a dedicated protection ring architecture

This paper describes and tests the feasibility of a protected super Ethernet passive optical network (Super-EPON). The architecture of the Super-EPON is based on a two-fiber ring that provides protection to the feeder section of the supported EPONs. The performance evaluation of the network is measured by simulating the behavior of dynamic bandwidth allocation (DBA) algorithms with quality of service (QoS) support in the upstream traffic management. The results are examined in terms of mean packet delay, mean bit rate per optical network unit (ONU), time-slot occupation efficiency, data packet loss, and overhead due to Ethernet headers and multi-point control protocol (MPCP) messages.

Response to the publication by Ueberall and Mueller-Schwefe

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